The present invention relates to a new and improved miniaturized surface mountable connector for connecting circuits on a printed circuit board to another circuit member. In a preferred embodiment, a new and improved miniaturized connector for electrically connecting the conductors of flat flex cable to printed circuits on a printed circuit board is provided.
Flat flexible cable or flexible printed circuits including parallel spaced electrical conductors disposed between upper and lower planar webs of insulation are known. Connectors for connecting the individual conductors of flat flexible cable to printed circuits on printed circuit boards are also known. Typically, in these connector arrangements an end of the flat flexible cable is pre-stripped so that the top layer of insulation is removed. This leaves the lower layer of insulation and exposed portions of the cable conductors extending along the upper surface of the lower insulative layer. Cable to board connectors for use with flat flexible cable typically include a unitary dielectric housing having a front end with an opening and a rear end with an opening, a lower board engaging surface and a socket extending between said openings. A plurality of metallic terminals are mounted in the housing, corresponding in number and spacing to the cable conductors. Each terminal typically includes a base portion disposed in the rear end of the housing, a pair of upper and lower spaced apart cantilever beams unitary with the base extending forwardly from opposed sides of the base into the socket. The separation between the upper and lower beams of the terminal define an insertion slot for receiving the pre-stripped end of the cable disposed in the socket. In addition, a rear contact portion extends rearwardly from the base of the terminal to provide for electrical engagement with the printed circuit on the printed circuit board.
A connector of this type further includes a cable actuator including a base and a forwardly projecting nose portion with an upper surface adapted to receive the flat flexible cable so that the exposed conductors of the prestripped end portion face away from the upper surface of the nose portion. The cable actuator is moveable toward the board mounted connector housing so that the nose portion of the actuator and the cable end are received into said socket and into said insertion slot defined between the cantilever beams of the terminal. As the nose portion of the actuator is inserted into the insertion slot it effectively pushes the exposed conductors on its surface into electrical engagement of the upper cantilever beams of the terminals within the housing. Typically latch means are provided on the actuator adapted to cooperate with latch recesses on the housing to lock the actuator and cable in mated position to the housing.
Connectors of this type may be fixed to a printed circuit board by soldering the board contact portion of each terminal to a conductive region on a printed circuit board. The terminal is affixed to the underlying printed circuit at a single point. Often a substantial length of the board contact portion extends along the upper surface of the circuit board. Typically the terminal to circuit solder connections are disposed to the rear of the connector housing. In use, the terminals may be easily raised up off the surface of the board if an external force is applied to a mated cable or to the housing. Unfortunately this may cause part of the printed circuit pattern to which the terminal is fixed to be removed from the printed circuit substrate.
In an effort to prevent terminals from rising and removing the underlying portions of the printed circuit pattern from the substrate, prior art connector housings have typically been provided with laterally extending flange members including depending mounting boss projections. The printed circuit board is also provided with mounting apertures which need to be drilled at precise locations in the substrate. Thereafter, the depending mounting projections must be press fitted into the mounting apertures to retain the housing in position on the printed circuit board. Alternate methods of securing a connector housing to a printed circuit board have included the provision of side mounting flanges including an aperture which is aligned with a printed circuit board mounting aperture and fixing members such as a nut and bolt or rivet arrangements are passed through the aligned apertures to permanently mount the connector to the printed circuit board.
These prior art methods of retaining the connector housing onto the printed circuit board have a number of disadvantages. The housing must be broader than the width of the circuits it is intended to overlie. This takes up real estate on the board surface area which could be used for additional circuitry. In addition, extra manufacturing steps are required to fix the connector housing to the printed circuit board and extra steps are required to provide mounting apertures in the printed circuit board. All of these requirements increase the manufacturing cost of the prior art connector arrangements. Moreover, these mounting arrangements do not meet the modern demand for increasing miniaturization of the connectors and for high density circuit boards having increased surface area utilized for bearing circuit patterns.